Bookmark context menu "Add folder..." allows to create folder with empty name(empty string).

chrome/browser/ui/cocoa/bookmarks/bookmark_name_folder_controller.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_name_folder_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
@@ skipping 79 matching lines @@
      didEndSelector:@selector(didEndSheet:returnCode:contextInfo:)
         contextInfo:nil];
 }
 
 - (IBAction)cancel:(id)sender {
   [NSApp endSheet:[self window]];
 }
 
 - (IBAction)ok:(id)sender {
   NSString* name = [nameField_ stringValue];
+  if (![name length])

[Alexei Svitkine (slow), 2014/08/14 19:27:11]

Nit: == 0 instead

[siba.samal, 2014/08/16 05:30:47]

Done.

+    name = l10n_util::GetNSStringWithFixup(IDS_BOOKMARK_EDITOR_NEW_FOLDER_NAME);
   BookmarkModel* model = BookmarkModelFactory::GetForProfile(profile_);
   if (node_) {
     model->SetTitle(node_, base::SysNSStringToUTF16(name));
   } else {
     model->AddFolder(parent_,
                      newIndex_,
                      base::SysNSStringToUTF16(name));
   }
   [NSApp endSheet:[self window]];
 }
@@ skipping 12 matching lines @@
 
 - (void)setFolderName:(NSString*)name {
   [nameField_ setStringValue:name];
 }
 
 - (NSButton*)okButton {
   return okButton_;
 }
 
 @end  // BookmarkNameFolderController